This disclosure relates to oxidizing fuel. Methane or other waste fuel gas produced by landfills or other sources may be used to fuel a gas turbine system. In a conventional gas turbine system, fuel is combusted as it is injected into pressurized air, thereby heating and increasing the energy of the gas. The energy is then extracted from the heated gas with a turbine which converts the energy into kinetic energy. The kinetic energy may be used to drive another device, for example, a generator. In some cases, the gas turbine system is temporarily shut down (e.g., for repairs, maintenance, or other reasons), and the source continues to produce methane and/or other gases that may be harmful if leaked into the Earth's atmosphere.